One approach - capture all the events in your code. Then, call a common method which uses the
sender
as the parameter. Change the back color of the sender.
Something like -
void textBox1_GotFocus(object sender, System.EventArgs e)
{
CommonColorChangerMethod(sender);
}
void CommonColorChangerMethod(object sender)
{
((TextBox)sender).BackColor = ....
}